734 research outputs found

    Intra-colonial Population of Macrotermes bellicosus (Smeathman) [Isoptera: Termitidae] in Sokoto, Semi-Arid Zone of North-Western Nigeria

    Get PDF
    The intra- colonial population of individuals within the mounds of mound- building termite, Macrotermes bellicosus (Smeathman) occurring in some selected Local Government Areas of Sokoto State were studied. A total of 72 cone shaped mounds were selected based on their heights. Populationswere estimated by randomly collecting and counting core samples from the mounds using a small bucket as the mounds were being excavated. At the end of the excavation, the total sand removed from the mound was crushed and measured using the same bucket. Total number of termites from a mound was extrapolated from the above estimates. Results indicate the presence of five different castes; reproductives, workers, minor and major soldiers and nymphs. The population of individuals per moundapart from the reproductives, ranged between 14158.00 and 24777.67 with an average of 18,795.49 termites per mound. The nymphs were the largest (5,942.60) closely followed by the workers (5,547.70), while the minor soldiers are the least with 3,279.38. Significant difference (p<0.05) occurred between minor soldiers and nymphs, major soldiers and nymphs, minor soldiers and workers and minor soldiers and nymphs in some of the studied areas. The present study show M. bellicosus to have high population within individual mounds enough to cause damage if ignored. Being a pestiferous species that could promote erosion, appropriate control strategies are required for its control.Key words: Macrotermes bellicosus, Mounds- building termites, intra-colonial Population, Mounds, Castes

    Comparison of various oxidative treatments for removal of reactive black CNN

    Get PDF
    Decolorization of reactive black CNN by chemical oxidation and reduction using KMnO4, H2O2 and Ferrioxalate as oxidizing agents and Na2SO3 as reducing agent individually as well as in combination was studied on batch scale using UV-visible spectroscopy. Degradation of dye occurred in acidic medium with KMnO4 and in alkaline medium with H2O2 and ferrioxalate. The most efficient methods for decolorization of reactive black CNN is oxidation using KMnO4 as an oxidizing agent which removed 97.64% of dye. Maximum decolorization was obtained at 60 min of treatment under static conditions. H2O2 and ferrioxalate could remove only 50.71 and 44.21% dye, respectively. Sequential treatment was more successful with H2O2 and ferrioxalate when compared with KMnO4. Chemical oxygen demand (COD) and total organic carbon (TOC) contents of treated wastewater decreased appreciably from 83.6 to 63.7 mg/L and 86.8 to 72.8 mg/L, respectively. Additionally, Fourier Transform Infrared Spectroscopy (FTIR) study revealed the degradation of reactive black CNN after treatment into non toxic products.Keywords: Reactive black CNN, KMnO4, ferrioxalate, sodium sulphite, chemical oxygen demand (COD)

    Embodied carbon determination in the transportation stage of prefabricated constructions: A micro-level model using the bin-packing algorithm and modal analysis model

    Get PDF
    The prefabricated construction generates considerable embodied carbon emissions during the manufacture, transportation, and construction stages. However, the contribution from the transportation stage is usually overlooked, leading to biases in life-cycle sustainability analysis of these projects. This article provides a micro-level transportation CE calculation method that estimates the project-specific emissions according to the features of prefabricated elements. The method simulates the transportation status of prefabricated elements as bin packing (BP) problems. Then, a modal analysis model is employed to calculate the CE of each vehicle based on vehicle type, road condition, and freight weight. Considering the minimum transportation CE as objective, a genetic algorithm is then used to search for the optimal solution and corresponding CE values. The comparative results among different CE calculation methods show that this BP-algorithm-based method provides reliable data across different loading rates, rendering the method suitable for calculating the transportation CE of prefabricated construction projects. Additionally, the BP-algorithm-based method differs the emission characteristics among different element typesβ€”the prefabricated floor generates the highest emissions, followed by prefabricated beam, wall, and columnβ€”suggesting the need to identify disparate emission factors for different element types and considering the sustainability aspects when selecting prefabricated approaches of projects. The results also highlight the efficiency of considering more prefabricated elements in a single transportation batch and selecting suitable vehicles for the optimisation of embodied carbon emissions. Architects, engineers, and contractors can use the method for project-specific transportation CE calculations and transportation planning. The calculation variables concerning the geometric features of prefabricated elements and vehicles can be adopted in the optimisation of project design and construction management for achieving less embodied carbon

    Zinc oxide nanoparticles selectively induce apoptosis in human cancer cells through reactive oxygen species

    Get PDF
    Mohd Javed Akhtar1,2, Maqusood Ahamed3, Sudhir Kumar1, MA Majeed Khan3, Javed Ahmad4, Salman A Alrokayan31Department of Zoology, University of Lucknow, Lucknow, India; 2Fibre Toxicology Division, CSIR-Indian Institute of Toxicology Research, Lucknow, India; 3King Abdullah Institute for Nanotechnology, King Saud University, Riyadh, Saudi Arabia; 4Department of Zoology, College of Science, King Saud University, Riyadh, Saudi ArabiaBackground: Zinc oxide nanoparticles (ZnO NPs) have received much attention for their implications in cancer therapy. It has been reported that ZnO NPs induce selective killing of cancer cells. However, the underlying molecular mechanisms behind the anticancer response of ZnO NPs remain unclear.Methods and results: We investigated the cytotoxicity of ZnO NPs against three types of cancer cells (human hepatocellular carcinoma HepG2, human lung adenocarcinoma A549, and human bronchial epithelial BEAS-2B) and two primary rat cells (astrocytes and hepatocytes). Results showed that ZnO NPs exert distinct effects on mammalian cell viability via killing of all three types of cancer cells while posing no impact on normal rat astrocytes and hepatocytes. The toxicity mechanisms of ZnO NPs were further investigated using human liver cancer HepG2 cells. Both the mRNA and protein levels of tumor suppressor gene p53 and apoptotic gene bax were upregulated while the antiapoptotic gene bcl-2 was downregulated in ZnO NP-treated HepG2 cells. ZnO NPs were also found to induce activity of caspase-3 enzyme, DNA fragmentation, reactive oxygen species generation, and oxidative stress in HepG2 cells.Conclusion: Overall, our data demonstrated that ZnO NPs selectively induce apoptosis in cancer cells, which is likely to be mediated by reactive oxygen species via p53 pathway, through which most of the anticancer drugs trigger apoptosis. This study provides preliminary guidance for the development of liver cancer therapy using ZnO NPs.Keywords: ZnO nanoparticles, cancer therapy, p53, apoptosis, RO

    Access to primary care and visits to emergency departments in England: a cross-sectional, population-based study

    Get PDF
    Background The number of visits to hospital emergency departments (EDs) in England has increased by 20% since 2007-08, placing unsustainable pressure on the National Health Service (NHS). Some patients attend EDs because they are unable to access primary care services. This study examined the association between access to primary care and ED visits in England. Methods A cross-sectional, population-based analysis of patients registered with 7,856 general practices in England was conducted, for the time period April 2010 to March 2011. The outcome measure was the number of self-referred discharged ED visits by the registered population of a general practice. The predictor variables were measures of patient-reported access to general practice services; these were entered into a negative binomial regression model with variables to control for the characteristics of patient populations, supply of general practitioners and travel times to health services. Main Result and Conclusion General practices providing more timely access to primary care had fewer self-referred discharged ED visits per registered patient (for the most accessible quintile of practices, RRβ€Š=β€Š0.898; P<0.001). Policy makers should consider improving timely access to primary care when developing plans to reduce ED utilisation

    Effect of phase fluctuation and dephasing on the dynamics of entanglement generation in a correlated emission laser

    Full text link
    A detailed study of the effects of phase fluctuation and dephasing on the dynamics of the entanglement generated from a coherently pumped correlated emission laser is presented. It is found that the time evolution of the entanglement is significantly reliant on the phase fluctuation and dephasing, particularly, at early stages of the lasing process. In the absence of external driving radiation, the degree of entanglement and intensity turns out to attain a maximum value just before starting to exhibit oscillation which dies at longer time scale. However, in case the driving mechanism is on, the oscillatory nature disappears due to the additional induced coherent superposition and the degree of entanglement would be larger at steady state. Moreover, the degree of entanglement as predicted by the logarithmic negativity and the Duan-Giedke-Cirac-Zoller criteria exhibits a similar nature when there is no driving radiation, although such a trend is eroded with increasing strength of the pumping radiation at longer time scale. The other important aspect of the phase fluctuation and dephasing is the possibility of relaxing the time at which the maximum entanglement is detected.Comment: 10 pages, 10 figure

    Magnified image spatial spectrum (MISS) microscopy for nanometer and millisecond scale label-free imaging

    Get PDF
    Label-free imaging of rapidly moving, sub-diffraction sized structures has important applications in both biology and material science, as it removes the limitations associated with fluorescence tagging. However, unlabeled nanoscale particles in suspension are difficult to image due to their transparency and fast Brownian motion. Here we describe a novel interferometric imaging technique referred to as Magnified Image Spatial Spectrum (MISS) microscopy, which overcomes these challenges. The MISS microscope provides quantitative phase information and enables dynamic light scattering investigations with an overall optical path length sensitivity of 0.95 nm at 833 frames per second acquisition rate. Using spatiotemporal filtering, we find that the sensitivity can be further pushed down to 10&amp;#8722;3-10&amp;#8722;2 nm. We demonstrate the instrument???s capability through colloidal nanoparticle sizing down to 20 nm diameter and measurements of live neuron membrane dynamics. MISS microscopy is implemented as an upgrade module to an existing microscope, which converts it into a powerful light scattering instrument. Thus, we anticipate that MISS will be adopted broadly for both material and life sciences applications

    Primary cilia elongation in response to interleukin-1 mediates the inflammatory response

    Get PDF
    Primary cilia are singular, cytoskeletal organelles present in the majority of mammalian cell types where they function as coordinating centres for mechanotransduction, Wnt and hedgehog signalling. The length of the primary cilium is proposed to modulate cilia function, governed in part by the activity of intraflagellar transport (IFT). In articular cartilage, primary cilia length is increased and hedgehog signaling activated in osteoarthritis (OA). Here, we examine primary cilia length with exposure to the quintessential inflammatory cytokine interleukin-1 (IL-1), which is up-regulated in OA. We then test the hypothesis that the cilium is involved in mediating the downstream inflammatory response. Primary chondrocytes treated with IL-1 exhibited a 50Β % increase in cilia length after 3Β h exposure. IL-1-induced cilia elongation was also observed in human fibroblasts. In chondrocytes, this elongation occurred via a protein kinase A (PKA)-dependent mechanism. G-protein coupled adenylate cyclase also regulated the length of chondrocyte primary cilia but not downstream of IL-1. Chondrocytes treated with IL-1 exhibit a characteristic increase in the release of the inflammatory chemokines, nitric oxide and prostaglandin E2. However, in cells with a mutation in IFT88 whereby the cilia structure is lost, this response to IL-1 was significantly attenuated and, in the case of nitric oxide, completely abolished. Inhibition of IL-1-induced cilia elongation by PKA inhibition also attenuated the chemokine response. These results suggest that cilia assembly regulates the response to inflammatory cytokines. Therefore, the cilia proteome may provide a novel therapeutic target for the treatment of inflammatory pathologies, including OA

    Improved hospital-level risk adjustment for surveillance of healthcare-associated bloodstream infections: a retrospective cohort study

    Get PDF
    Background: To allow direct comparison of bloodstream infection (BSI) rates between hospitals for performance measurement, observed rates need to be risk adjusted according to the types of patients cared for by the hospital. However, attribute data on all individual patients are often unavailable and hospital-level risk adjustment needs to be done using indirect indicator variables of patient case mix, such as hospital level. We aimed to identify medical services associated with high or low BSI rates, and to evaluate the services provided by the hospital as indicators that can be used for more objective hospital-level risk adjustment

    Interleukin-1Ξ² sequesters hypoxia inducible factor 2Ξ± to the primary cilium.

    Get PDF
    BACKGROUND: The primary cilium coordinates signalling in development, health and disease. Previously we have shown that the cilium is essential for the anabolic response to loading and the inflammatory response to interleukin-1Ξ² (IL-1Ξ²). We have also shown the primary cilium elongates in response to IL-1Ξ² exposure. Both anabolic phenotype and inflammatory pathology are proposed to be dependent on hypoxia-inducible factor 2 alpha (HIF-2Ξ±). The present study tests the hypothesis that an association exists between the primary cilium and HIFs in inflammatory signalling. RESULTS: Here we show, in articular chondrocytes, that IL-1Ξ²-induces primary cilia elongation with alterations to cilia trafficking of arl13b. This elongation is associated with a transient increase in HIF-2Ξ± expression and accumulation in the primary cilium. Prolyl hydroxylase inhibition results in primary cilia elongation also associated with accumulation of HIF-2Ξ± in the ciliary base and axoneme. This recruitment and the associated cilia elongation is not inhibited by blockade of HIFΞ± transcription activity or rescue of basal HIF-2Ξ± expression. Hypomorphic mutation to intraflagellar transport protein IFT88 results in limited ciliogenesis. This is associated with increased HIF-2Ξ± expression and inhibited response to prolyl hydroxylase inhibition. CONCLUSIONS: These findings suggest that ciliary sequestration of HIF-2Ξ± provides negative regulation of HIF-2Ξ± expression and potentially activity. This study indicates, for the first time, that the primary cilium regulates HIF signalling during inflammation
    • …
    corecore